Guide to Being 10 Weeks Pregnant

The nausea that's plagued the first nine weeks of your pregnancy may not be gone, but it's beginning to wane. Until now, being a new mom felt a lot like the flu, but something thrilling happens at the 10- week mark that makes your pregnancy seem very real: Hearing your baby's heartbeat for the first time.

Typically, your doctor will use a Doppler device to listen for a heartbeat during a routine office visit. This handheld machine uses sound waves to locate and hear heart tones and then transmits the sound through a built-in speaker. If an attempt to hear your baby's heartbeat fails, it's not necessarily cause for alarm. The position of the uterus, the position of the baby in the uterus or the position of the placenta could all be reasons. Plus, most women have a fat layer above the pubic bone, directly over where a baby would be located at 10 weeks. This can make it difficult to hear a heartbeat, too.

Don't worry if you don't hear your baby's heartbeat yet; in just a week or two your baby will be larger and her heart tones will be easier to locate.

You may have noticed traces of blood on your toothbrush or that your gums are swollen and red. These changes, known as "pregnancy gingivitis," are caused by hormone surges and usually resolve after your baby is born. Unfortunately, dental problems could also signal more serious problems and affect the health of your baby. According to the American Academy of Periodontology, pregnant women with periodontal disease are up to seven times more likely to give birth to a preterm, low-birth-weight baby. This means a dental appointment should be one of the first trimester's don't-miss events.

Hormonal changes during pregnancy also affect your eyes and become noticeable during Week 10. The cornea, which is the outer layer of your eye, thickens because of fluid retention. Even with all this extra fluid sloshing around your cells, your eyes will often feel drier than normal. You may also notice slight swelling of the eyelids. Although these changes are normal and only temporary, tell your doctor if your vision becomes blurry or if you see spots. These could be signs of elevated blood pressure or increased blood sugar.

Your partner can't see much evidence of your pregnancy yet (other than a tiny baby bump and the flu-like symptoms you've been feeling), but you can still map your baby's progress together. Ask him to go with you to your prenatal visits. It's a great way to get questions answered, to bond and to understand more about baby's development.

By Week 10, your baby has moved past the embryonic stage and is now officially a fetus. She's about the size of a lime and is less at risk for physical birth defects. She has fingers and toes to wiggle and has formed all of her internal organs. Vital organs, including the liver, kidneys, intestines and brain, kick into action. Your baby's brain, for example, is producing 250,000 new brain cells every minute. It's no wonder her head is about half her total length!

If you were to look closely at your baby, you'd notice she doesn't look like a tadpole anymore. Her embryonic tail, located at the bottom of the spinal cord, has disappeared and her rapidly developing spinal nerves have become visible. Her eye color has been determined and the irises are forming. The eyelids are fused shut and will not open again until Week 25.

Exercise is important during pregnancy. Not only does it help prepare your body for labor and delivery, but it also helps you manage the physical changes you'll experience in the coming months.

You should consult your doctor about types and amounts of exercise. In general, it's OK to continue exercises you were frequently doing before pregnancy. But even if you were a daily runner, you may want to select a low-impact activity for the duration of your pregnancy. Walking is an excellent choice, and something you can do up until delivery. Swimming is another option. It works nearly every muscle in the body while allowing you to take advantage of the water's buoyancy.

For dry land workouts, buy a supportive maternity bra. Sure, you may own a drawer full of sports bras, but they're no match for your growing -- and increasingly sensitive -- breasts. A custom fit is key, so take a few measurements before you shop. Place a measuring tape under your arms and around your body to record the band size. Then, place a measuring tape around the fullest part of your bust to record the cup size.

At the 10-week mark, your doctor may ask whether you'd like a CVS test to reveal genetic conditions like Down syndrome. Chorionic villus sampling is recommended to women age 35 and older, and women with a family history of genetic disorders. A catheter is inserted into the vagina and through the cervix to remove a small sample of placenta. Or, a needle is inserted into the abdomen. Regardless of method, CVS is one of the more invasive tests performed during pregnancy; there is a 1 in 100 chance it could trigger a miscarriage.

So why consent to the test? The results, which are available within seven to 14 days, are 99 percent accurate when it comes to diagnosing many genetic and chromosomal abnormalities. And, unlike an amniocentesis test that can only be given in the second trimester, you receive CVS results before your first trimester ends. Keep in mind, however, that a CVS test doesn't rule every abnormality.

Week 10 also is a good time to revisit the importance of prenatal supplements. Powdered or liquid prenatal vitamins are easier to swallow than those in pill form and won't wreak as much digestive havoc.